P0420 on CHEVROLET EQUINOX

"I put in a new cadillac converter and every time i turn around i have to change the o2 sensors bank1 02 sensor keeps giving me p034 & p054 in a permanent p0420 it gets very expensive changing the same repairs over and over again ."

"I just recently bought a 2011 chevy equinox lt awd, and soon after i began driving it, the check engine light came on with code p0420 catalyst system efficiency below threshold."

"Rattle and noise in the front passenger side of vehicle as soon as vehicle is turned on and while in motion, making weird noises and movements while driving, occasional hard shift, back rear drivers tire losing pressure for no reason, pulling code for p0420, did a google search and seen multiple com"

"Driving down the highway going about 70 miles per hour over a bridge. my vehicle started loosing power. about 2 miles after the bridge the engine light came on and the engine shut off. never came back on."

"For the second time since i have owned the car new major engine work was undertaken. 1st was a timing chain wear issue causing engine noise at about 50k miles. next was a near total engine rebuild due to excess oil consumption where rings, bearings, pistons etc at gm warranty cost."